1. Field
An embodiment of the invention relates to a fluxing agent for an underfill material.
2. Background Information
No flow underfill materials for microelectronic packages often contain fluxing agents to help remove metal oxides from solder bumps during solder reflow. Commonly employed fluxing agents include low molecular weight carboxylic acids and anhydrides. A potential problem with employing such low molecular weight agents is that voids may form due to vaporization of the fluxing agents during the elevated temperatures used during reflow or underfill material curing. The voids may concentrate thermomechanical stresses, trap undesired moisture, or otherwise reduce the effectiveness of the underfill material and degrade device reliability. Another potential problem, when employing carboxylic acids, is premature reaction with the underfill material, which may potentially lead to increased viscosity, poor solder joint formation, and reduce production yields.